Alexander t



of the lower part of the leg, as represented by the dotted lines Z Z.

ALEXANDER T. WATSON, or NEW Your., N. Y.

Letters Patent No. 61,780, dated Efbruarg/ 5, 1867.

IMPROVEMENT IN ARTIFICIAL LEGS.

,TO ALL WHOM IT MAY CONOERN:

Be it known that I, ALEXANDER T. WATSON, of the city, county, and State of New York, have invented a y 119W and useful Improvement in Artificial Legs and I do hereby declare thatthe following is a vfull and exact description thereof, reference being had to the accompanying drawings, and to the letters of reference marked thereon, in whichvFigure I represents the artificial leg suitable for axnputations at or above the knee, themeans of attachment to the thigh being represented in perspective. v

Figure II is a cross-section of the knee'joint; and

Figure III is a view of an articial leg partly in section, as adapted to amputations below vthe knee.

vThe object of my said invention is to produce an artificial leg, approximating to the skeleton of the human leg, but capable of being lengthened or shortened, and expanded or contracted in the 'direction of the circumference, at pleasure, so as tosuit any ordinary-sized person, and which maybe applied to any amputation of the thigh, leg, or foot, and which may be used for the right or left, as required.

In the accompanying drawings, Eig. I, .a a represents the articial foot, which I prefer to make of wood, in the form of a last, cut in two in a longitudinal vertical plane. The inside is partially cut out, as represented,- taking cure to leave sufficient thickness of wood for the required strength, `atc c. The toe part is. separated and cut away from the upper part, and the two parts, so separated, are then connected by a hnge-joint, sovthat lthe toe end b may yield in walking, whilst, at the saine time, a spring, to be presently described, tends to carry it back to a natural position. The foot, formed as before described, or in any analogous manner, is then connected with the leg by a fulcrum-bolt passing horizontally :through the foot, to which it is firmly secured by a nut and screw on one end of Vsaid bolt; this bolt also passe's through the bolt-hole in th'emetallic segment at d. The lower part of the periphery of said segment is fitted to turn in a socket formed in the inside of the foot at e e, so that the fulcrum or ankle-joint bolt need not sustain the whole weight. The hole in this metal segment d is slightly enlarged towardsV each end, to enable the fulcrunu or ankle-joint bolt to vibrate in it laterally, that the foot may turn slightly. A spring,f, is fitted and secured to the upper part of the segment d, and the front end of it curves downto rest on the bottomof the inside of the foot, and extends into the cav'ity of the hinged toe piece l, and the rear end of the said spring curves down into the cavity of the heel, and rests on the bottom thereof, so that when the foot in waflkingis thrown forward, and the -heel rst strikes the ground, the spring will permit it to yield downwards, and-as the foot falls back by the forward motion of the body, the front part of the spring will yield and allow the front part of the' foot to yield upwards, and, finally, the toe' piece will yield upwards, thus causing the foot-'to yield and return to the original position, as the natural foot does in Walking. To gireY greater power of resistance to the heel, I prefer te make the spring f double at the rear end, asV represented, or more springs may' he added, if` necessary, the Ieaves being separated at some distance,oue from the other, .so as to'be brought into action one after the-other, as-pressure is made on the heel. foot on which the spring bea-rs, I prefer to'line with leather or other substance more yielding than wood. The leg piece h h is in two parts, an vupper and lower; the upper part having a screw, 1,' z', passing through a hole in the head of the-lower part in the transverse piece at o, and entering into a chainber drilled in the lower portion m m are guide-rods descending in front and rear of the screwz' z', and are secured to the cross-piece n' u of the upper portion of the leg, and through holes in the cross-piece o o of the lower portion of the leg. The action of the guide-rods is to prevent the foot V'from turning. The lower end of the lower part ofthe leg 72. is solid, and so formed, as represented, that it can be rmly secured to the upper'part of the segment d by the screw g, which, at the same time, lsecures the springf, which` is interposed as represented `betweenthc lower end of the leg and the segment d. Binding or jam-nuts are placed on the screw z', one above and the other below the cross-piece o o, and hold the upper and lower part of the leg firmly together when the requiredlength has been obtained. Other and equivalent means may be substituted for adjusting the length and for holding the parts firmly when set, and to prevent the one part from turning on the other, viz, the same effect may be produced by tubes sliding one within the other, as a telescope, and having within a right and left screw to lengthen and shorten, The upper part Yof the upperportion Vofthe leg is bifurcated, (F ig. I, p, Fig. II, 102 112,) forming ,about a semicirele, and their upper ends are itted to turn on the ends ot' an axle, Fig. II, :v2 'm2, which forms the knee-joint. From thev middle of this axle an arm The parts of the 'extends down, and its ex treme end is attached to or makes part of a segment, q, (Fig. I, g2, Fig. 11,) the upper ends .of which are secured to a loop r r, Fig. Il, through the diameter of which the axle 2:2 9:2 extends, and to which it is secured, so that the loop is between the two bifurcatbns 112122 of the upper vportion of the leg. The upper end of the upper portion of the leg, and before it bifurcates, is slotted, and within this slot is mounted a frictionroller, (Fig. II, o", Fig.` I, dotted lines 0,) which rolls against the periphery of the segment q", (Fig. II, q, Fig. L) the extent of which below the loop r -r, Fig. II, is a semicircle, and this segment is formed with a shoulder, (Fig. s, on each side and alittle forward of the middle, to act as stops to the upper part of the leg to prevent it moving forward of a vertical, or nearly vertical, line when the person is standing up. In -this way the leg can move on the'axle :v2 .2:2 as a knee-joint to the. extent ot'iabout a quarter o f a circle, and there are two springs t t, Fig. II, attached to the axle x2 x2, and tothe upper part of the upper portion of the leg at u u, the tension of which will bringfbacli the leg in line with the thigh, whenever it is liberated, either when walking or in rising from a seat. I The lower ends of the four straps 1v zu w u', which I prefer to make of metal, are secured to the hoop o v, and cach of these straps is made of two parts, w" wi', lapped and slotted longitudinally to secure ilatheaded screws ze z2 z2, Vby which the two parts are held together, but by' means of which the length can be increased or decreased to meet thc length of the thigh to whiehtbey are to be applied; and' there are three other at hoops, 1 2 3, secured to. the' straps by means of fiat-headed screw bolts d2 d'l di, and the said hoops are formed with lap-joints slotted and secured by {iat-headed screw bolts, so that their circumference can be varied to suit the person to which an artificial limb is to beV applied; felt, leather, or other suitable material being interposed between the stump and the metal hoops and straps to form a socket for the protection of said Stump.

The' modification of my invention to suit an'amputation of the leg below the knee is represented in Fig. III of the accompanying drawings. In such modification, the mechanism above the knee, and as described, is not required- Hoops, such as in Fig. I, are required to be applied to the stump of the leg, and connected with four longitudinal straps; two do not extend above the hoop next below the knee, but the two side ones extend up to the knee-joint, and are there to be connected by rule joints .to the side thigh straps. The thigh straps are to be secured to the thigh by adjustable hoops, as for amputation above the knee.

It will be obvious, from the foregoing, that some of my said improvements may be used without others-by substituting other means, and therefore I do not wish to be' understood as limiting my claim of invention 'to -the use of all my hsaid improvements in combination or connection.

h Claims.

'What I claim as my invention, and desire to secure by Letters Patent, is

The connection of the foot with the leg by means of the joint, substantially as described, in combination with the springs extended both ways, for action at the heel and at the toes, substantially and for the purposes described.

I also claim the toe piece hinged to the front part of the foot, substantially as described, in combination with the spring which controls the movements, substantially as described.

I also claim the leg made in two parts and adjustable in length, substantially as described, or any equivalent thereof for adjusting the length of the leg.

I also claim fthe .adjustable longitudinal straps and the adjustable hoops in combination, substantially as described, as a. means of fastening the artificial leg to the thigh or to the stump of the leg, as described.

I also claim the knee-joint, substantiallyv as described, Iin combination with the leg and foot or their equivalents. i

ALEX. T. WATSON.

Witnesses z i N. C. TnMrLEToN,

G. S. Lor'r. 

